Engine Braking the TDI.......

[Trumpetman21]

Talking of engine braking, it's funny to see someone on a motorcycle getting it wrong and locking the back wheel when changing down too quickly....new pair of kecks methinks!

Slipper clutches all the way!

 

[Wheely]

Post has done well on opening up a range of views.

Thanks for all the feedback -- you telling me its both good and unharmful yet bad and damaging. LOL

No, I do think its promoted some interesting thoughts and feedback.

In the context of my initial post, I am not doing this whilst flying, as I'm no racing driver, I like my bit of speed now and then - and the car is nicely up for it -- but where I've started to use the engine braking (or is now engine breaking !!) is on known junctions/lights when I'm commuting that same stretch of road I always go to work along. Basically I'm slowing down a whole bunch earlier, being a bit lazy and deccelerating to the lights. No boy racer style in this at all.

Now if you want to talk about proper down shifting, lets talk about my ZX6 Ninja motorbike which comes with a slipper clutch as standard. Means I can bash the thing down through the box, and the clutch automatically slips to prevent the rear wheel locking under the immense engine/gearbox braking whilst the backend is further lightened by huge amounts of front brake !!!! Now thats a clutch designed for down-shifting fun.

So there's my context of it all !!

Sounds to me like what I am doing in the car is really going to cause minimal wear/problems. But if I start to do this in anger, well expect some accelerated wear rates on certain drivetrain components.

MARK

 

[Wheely]

Talking of engine braking, it's funny to see someone on a motorcycle getting it wrong and locking the back wheel when changing down too quickly....new pair of kecks methinks!

Slipper clutches all the way!

How did you know i was typing that as you posted !!!!! Freaky

 

[Trumpetman21]

How did you know i was typing that as you posted !!!!! Freaky

I didn't (honest!), just thought I'd add my two'penneth as a fellow motorcyclist. Closest I've got to locking the back wheel (CBR600F4 - no slipper clutch) is a bit of fish-tailing into a roundabout but I've been behind a mate on a SP-2 who's f*cked it up big-time and locked it up....as I wasn't far behind him at the time I had a bit of an adrenaline rush too I can tell you!

 

[EdButler]

You can't heel and toe, because the ECU cuts the fuel when braking. IIRC this isn't just in the TDIs - i don't think i could in the Octy I vRS i tried. Must be a silly VAG thing ;-)

/Rich

Someone has told me this before but its definitely not the case in my car - i dont kniow if it's because mine is remapped, but engine responsiveness is the same when on the brakes as to when off...

Can anyone shed any light on it?

 

[Muttley]

richard_jerome wrote
You can't heel and toe, because the ECU cuts the fuel when braking. IIRC this isn't just in the TDIs - i don't think i could in the Octy I vRS i tried. Must be a silly VAG thing ;-)


EdButler wrote
Someone has told me this before but its definitely not the case in my car - i dont kniow if it's because mine is remapped, but engine responsiveness is the same when on the brakes as to when off...

Can anyone shed any light on it?

The TDI system has sensor switches on brake and clutch pedals. The brake sensor is a safety device, in case the throttle sensor fails in a full-on sense, and it tells the ecu to go to idle. Diesels have no throttle butterfly, and can fail in a full-power mode: this is why lorry drivers used to carry toffee-hammers, to knock the injector pipes off if this happened to them, to stop the engine revving itself to bits.

The clutch sensor just drops the revs a bit to "ease gearchanges".

Some VAG petrol engines have a clutch sensor which releases the throttle damper for a fast return to idle. Don't know of any other clutch or brake function on the petrol systems, but then I drive a diesel